Polyhydroxy Acid - The Acid You Should Know About

No doubt you are familiar with glycolic acid, salicylic acid and lactic acid by now, and if you're anything like us, at least one of them is your best friend and saviour. 

The hot acid on the scene right now goes by the moniker of PHA, or polyhydroxy acid. Don't be fooled by its supposedly sudden arrival because its not a new discovery at all. Like AHAs, they were discovered by the very same dynamic duo that brought us Neostrata and Exuviance, Dr. Eugene Van Scott and Dr. Ruey Yu, in the 1990s, and because of this, they have always featured heavily in both of the aforementioned brands.  

What is PHA? 

PHA is actually a type of AHA, described as a second-generation alpha hydroxy acid. Compared to AHAs like glycolic acid and lactic acid, PHAs have a larger molecular size. This sounds random until we explain that the molecular size of an acid is what determines how quickly it can penetrate into the skin.

The larger it is, the slower it is at getting to work and this is a good thing, not a bad thing, as it means a lower likelihood of irritation whilst still being effective. Essentially, PHAs exfoliate the skin without exfoliating it too much - so long as they are used correctly.

What do PHAs do? 

PHAs have other qualities that aren't shared by all AHAs... 

  • They are water-binding, meaning better skin hydration 
  • They specifically fight glycation, the word used to explain the process of unchecked sugars in your blood causing damage to your collagen and elastin 
  • They assist in repairing the epidermis and building up our skin's barrier in certain percentages 
  • They provide the skin with antioxidant protection 
  • They do not cause the skin to become more sensitive to light, like AHAs can 
  • They can even be used by those with rosacea and eczema as they are a reparative ingredient

The two key PHAs you'll come across are gluconolactone and lactobionic acid.   

Our nerdie pick of PHA products

Neostrata Restore Bionic Face Cream (€53.50) 

The Neostrata Restore Bionic Face Cream is a moisturising cream with PHAs to draw hydration into the skin and reduce the appearance of lines and wrinkles. It plumps, smoothes and softens and can be used alongside your other acids without a second thought. Neostrata recommend usage after procedures such as peels and laser as a means of helping the skin to heal quickly. 

Suitable for all hoomans as it is non-comedogenic and fragrance-free.


Neostrata Targeted PHA Eye Cream (€48.95)

With 4% gluconolactone and antioxidants green tea extract and vitamin E, this strengthens the skin around the eye area, plumps it up and reduces the appearance of lines. In case you were wondering, you'll also find hydrators such as hyaluronic acid, evening primrose oil and avocado oil in here. 

Perfect for mature skin or those with irritated eye areas. 

Neostrata Restore Facial Cleanser (€32.50) 

With 4% gluconolactone, this is the ideal cleanser to use alongside your exfoliating cleanser. It very gently exfoliates the skin, helping to strengthen it rather than strip it. 

Particularly fantastic for those with dry, dehydrated or irritated skin, or skin with an impaired barrier.


If you want more information on where PHAs could fit into your routine, book in for a follow-up consultation.